1. Field of the Invention
The present invention relates to a zeolite membrane and a process for producing a zeolite membrane.
2. Description of Related Art
Zeolite is used as a catalyst, a catalyst carrier, an adsorber, or the like. A zeolite membrane-provided body wherein a membrane is formed on a surface of the porous substrate made of metal or ceramic uses a zeolite molecular sieve function and is used as a gas separation membrane and a pervaporation membrane.
There are present many kinds (types) of zeolite such as LTA, MFI, MOR, FER, FAU, and DDR. For example, a DDR (Deca-Dodecasil 3R) type zeolite contains silica as the main component and is formed by a polyhedron containing pores having an oxygen eight-membered ring having a pore diameter of 4.4×3.6 angstrom. Since the DDR type zeolite has a small pore diameter, the use as a molecular sieve membrane for low molecular gas such as carbon dioxide (CO2), methane (CH4), ethane (C2H6).
For example, Patent Document 1 discloses a process for producing a zeolite membrane, where a DDR type zeolite membrane is formed by immersing a porous substrate in a raw material solution containing 1-adamantanamine, silica, and water for hydrothermal synthesis of a DDR type zeolite in the presence of a DDR type zeolite seed crystal.
In addition, Patent Document 2 discloses a process for producing a zeolite membrane using a raw material solution containing a DDR type zeolite powder.